If you're interested in LiDAR data from the United states, you should have a look at this wikipedia page and its corresponding links[0]. Most states have some kind of data freely available from the most recent survey, although it's neither uniform or always clear in terms of how to access it. The structure of the program allowed individual states to tackle their won territory differently in both surveying and data dissemination, so there's no easy and official central repo as far as I understand.

I was in grad school at Indiana and working at the geological survey while they were finalizing some of the state's pieces of this, and it was really fascinating to see some of the early products some of the people in the geography and geology departments were producing. I mucked around a bit with it myself, but never really produced anything useful. I can speak to finding the data fairly easy to acquire and quite comprehensive at the time, uncertain if that's changed, but might be a decent starting point[1].